MT LAUREL, New Jersey — Iridium Communications is less than a week away from the final launch of its 75-satellite Iridium Next constellation, but could opt to launch six ground spares sooner than later should the right rideshare opportunity open up, CEO Matt Desch said Jan. 3.

Iridium’s final six second-generation satellites should finish construction by February if not sooner, Desch said during a call with reporters. Northrop Grumman Innovation Systems and Thales Alenia Space are building all 81 satellites in total.

Desch said Iridium is in no rush to orbit the final spares. Iridium Next, following the upcoming Jan. 8 SpaceX Falcon 9 launch, will already have a full complement of nine orbiting spares as backup for the 66 operational satellites. But spare satellites keep better in space than they do on the ground, Desch said.

“More than anything else, it’s going to be very opportunistic to put those into space because there’s really not a need for them anytime soon,” Desch said. “If the right deal comes along, similar to the one that we had with Iridium-6 and the rideshare that we had with NASA. That really worked out extremely well … I would expect it’s going to be another deal like that.”

Iridium already increased the number of orbital spares in Iridium Next once in 2017. The company originally planned to orbit six spare satellites, but increased that number to nine when the opportunity arose to split a launch with a U.S.-German Earth science mission. Iridium launched five Iridium Next satellites with the twin GRACE-FO satellites in May 2018, re-manifesting two satellites that were supposed to launch on a Russian-Ukrainian Dnepr mission that never happened, plus three additional Iridium Next satellites.

Iridium won’t actively seek such a launch opportunity, though, he said. The company’s preference is to lower spending in order to pay down debt on the $3 billion Iridium Next constellation.

“We really like the idea of a capex holiday for 10 or more years and that would sort of break that,” he said. “But if it’s a smart rideshare with someone else, then that could be a very cost-effective way to get those ground satellites into space.”

Desch said the 65 Iridium Next satellites already in orbit are working “extremely well,” and that the baseline plan of nine spares should be sufficient to support the constellation for its full life.

Iridium Next satellites should enable 15 to 20 years of service, he said. He said the second-generation satellites are built much hardier than the original constellation, which had numerous early failures when it launched in the late 1990s.

Desch said SpaceX’s Jan. 8 launch will bring to 170 the total number of Iridium satellites put into space over the company’s history.

Desch said just six of the original Block 1 satellites remain in use, all of which will be replaced by the Jan. 8 launch.

So far 46 Block 1 satellites have deorbited, Desch said. Another six have been “deboosted,” he said, where their orbits are lowered, fuel tanks depleted, batteries drained and solar panels angled for maximum atmospheric drag. Desch estimated the time between deboosting and deorbiting averages less than a month.

Iridium keeps Block 1 satellites in a lower orbit about 15 kilometers below Iridium Next until the company is ready to dispose of them. The company anticipates fully deorbiting the entire Block 1 constellation early this year.